A Bi 3+ and Y 3+ Co-doped AgNbO3 antiferroelectric energy storage ceramic material, preparation method and application thereof

Abstract

The application discloses a kind of Bi 3+ And Y 3+ Co-doped AgNbO3 antiferroelectric energy storage ceramic material and preparation method and application thereof, the chemical formula of the energy storage ceramic material is Ag 1‑3x Bi x Nb 1‑3x / 5 Y x O3, wherein 0 3+ And Y 3+ Co-doped AgNbO3 antiferroelectric energy storage ceramic material is in A / B site.The application also specifically discloses preparation method of the Bi 3+ And Y 3+ Co-doped AgNbO3 antiferroelectric energy storage ceramic material and application thereof in preparation of ceramic capacitor.The application prepares AgNbO3-based antiferroelectric energy storage ceramic material with pbcm space group perovskite structure by simple, easy-to-implement technical process, improves its breakdown field strength (E b ) While also reducing the remanent polarization value (P r ), and can effectively improve energy storage density and the stability of antiferroelectric phase at room temperature.

Description

TECHNICAL FIELD

[0001] The application belongs to the technical field of dielectric energy storage ceramic materials in ceramic capacitors, and particularly relates to a Bi 3+ and Y 3+ co-doped AgNbO3 antiferroelectric energy storage ceramic material, a preparation method and application thereof. BACKGROUND

[0002] Ceramic-based dielectric capacitors have ultra-high power density and excellent fatigue resistance, and are considered as one of the excellent candidate materials for high pulse power devices, such as electric vehicles, smart grids, aerospace and automotive industries, pulse power weapons, etc. However, compared with other energy storage devices (fuel cells, batteries, supercapacitors), the recoverable energy density of dielectric capacitors is limited, which is about 1-2 orders of magnitude smaller than that of lithium-ion batteries, which seriously limits its application in the miniaturization and integration of pulse power systems. Therefore, the main task for the wide industrialization of dielectric capacitors is to improve the energy storage density so as to be comparable to electrochemical capacitors. As the core component of dielectric capacitors, dielectric energy storage materials are the key.

[0003] At present, the commercial dielectric energy storage materials are mainly lead-based ceramic materials, such as lead titanate (PbTiO3) and lead zirconate titanate (PZT). Recently, the reported energy storage density (W rec ), energy storage efficiency (η) and breakdown field strength (E b ) of lead-based energy storage ceramic materials reach 11.2 J / cm, 82% and 400 kV / cm respectively, which shows that lead-based ceramic materials have excellent energy storage characteristics. However, the lead-containing substances produced in the preparation process of lead-based ceramic materials seriously pollute the environment, and the Pb content in 100 g of PbTiO3 is as high as 68 g. In the use of lead-based ferroelectric materials at a higher temperature, the risk of leakage of toxic lead is increased. Due to the increasingly stringent environmental protection requirements and the need for energy industry transformation, "lead-containing" to "lead-free" has become a new hotspot in the field of energy storage. Therefore, it is of great significance to develop a lead-free antiferroelectric energy storage ceramic material with excellent performance.

[0004] At present, the research hotspot of lead-free energy storage materials mainly focuses on ferroelectric BaTiO3, relaxor ferroelectric Bi 0.5 Na 0.5 TiO3 and antiferroelectric AgNbO3 materials. Among them, the relaxor ferroelectric Bi 0.5 Na 0.5 TiO3 ceramic material has a monotonous decrease in polarization hysteresis, forms a relatively fine P-E loop, and improves the conversion efficiency, but the energy storage density is low; the lead-free antiferroelectric AgNbO3 ceramic material has a high P max (P max ~ 50 μC / cm 2) and high Curie temperature (T c ~350℃) has attracted extensive attention. However, pure AgNbO3 ceramic material is considered to coexist with antiferroelectric phase AFE (Pbcm) and ferroelectric phase (Pmc21) at room temperature, resulting in considerable hysteresis and obvious non-zero remnant polarization (P r ), which has a negative impact on the energy storage performance of AgNbO3 ceramic material. AgNbO3 ceramic material also has low breakdown field strength, unstable antiferroelectric phase, and other problems that limit the improvement of energy storage performance and hinder its further commercial application.

[0005] In the prior art, patent document with application number 202211559128.2 discloses AgNbO3 antiferroelectric energy storage ceramic prepared by hydrothermal reaction method, the preparation process of which is relatively complex, and the energy storage density of the finally prepared energy storage ceramic is 3.8-4.5 J / cm 3 , and the conversion efficiency is 38.5%-45.1%, which is not ideal.

[0006] In the prior art, patent document with application number 201911420679.9 discloses Ag 0.97 Nd 0.01 NbO3 antiferroelectric energy storage ceramic prepared by solid phase reaction method, the sintering temperature of which is relatively high (sintering temperature is 1150℃), and the conversion efficiency of the finally prepared energy storage ceramic is only 50.2%.

[0007] In the prior art, patent document with application number 202111194580.9 discloses (1-x)AgNbO3-x(Sr 0.7 Bi 0.2 )HfO3-0.01BCB antiferroelectric energy storage ceramic prepared by solid phase reaction method, although the energy storage density of the energy storage ceramic can reach 6.1 J / cm 3 , and the energy storage efficiency can reach 73%, but the preparation process steps are relatively cumbersome, and the composition is complex, which is not easy to realize.

[0008] In the prior art, patent document with application number 202210536338.3 discloses the chemical formula of lead-free antiferroelectric high energy storage density ceramic material is (1-x)(Na 0.5 Ag 0.5 ) 1-3y M yNbO3-xABO3, wherein 0 < x ≤ 0.3, 0 < y ≤ 0.15; ABO3 is selected from one of BiFeO3, NaTaO3 and AgTaO3; M in the general formula is selected from one or more of Bi, La, Ce trivalent metal oxides, and when more than one, the sum of the mole fraction is 1; by combining the advantages of the two lead-free antiferroelectric bodies of NaNbO3 and AgNbO3, a (Na 0.5 Ag 0.5 )NbO3 matrix is constructed, and by substituting A-site with high-valence elements, Ag reduction is inhibited, and when other perovskite compositions are added to (Na 0.5 Ag 0.5 )NbO3, a stable and reversible antiferroelectric phase structure can be obtained, and finally a high energy storage density is obtained, which can meet the practical application requirements in lead-free energy storage capacitors.

[0009] Therefore, on the basis of optimizing the preparation process of AgNbO3 antiferroelectric energy storage ceramic material, how to stabilize the antiferroelectric phase of AgNbO3 ceramic material at room temperature, enhance its relaxation behavior, and realize high W rec and η become a key technical problem in the field. SUMMARY

[0010] The technical problem solved by the present application is to provide a Bi 3+ and Y 3+ co-doped AgNbO3 antiferroelectric energy storage ceramic material and a preparation method thereof, which simplifies the preparation process of AgNbO3 antiferroelectric energy storage ceramic material, solves the stability of its antiferroelectric phase at room temperature, effectively improves its energy storage density and conversion efficiency, and can be further used for preparing AgNbO3-based high-performance ceramic capacitors.

[0011] The technical problem solved by the present application is to provide a Bi 3+ and Y 3+ co-doped AgNbO3 antiferroelectric energy storage ceramic material and a preparation method thereof, which simplifies the preparation process of AgNbO3 antiferroelectric energy storage ceramic material, solves the stability of its antiferroelectric phase at room temperature, effectively improves its energy storage density and conversion efficiency, and can be further used for preparing AgNbO3-based high-performance ceramic capacitors. 1-3x Bi x Nb 1-3x / 5 Y x O3, wherein 0 < x ≤ 0.01, Bi 3+ and Y 3+ co-dope AgNbO3 antiferroelectric energy storage ceramic material at A / B sites.

[0012] Preferably, the chemical formula of the energy storage ceramic material is Ag 0.97 Bi 0.01 Nb 0.994 Y 0.01 O3, and the energy storage density W rec = 5.4 J / cm3 , conversion efficiency η = 56%, breakdown field strength E b = 190 kV / cm.

[0013] A Bi 3+ and Y 3+ co-doped AgNbO3 antiferroelectric energy storage ceramic material preparation method, characterized in that the specific steps are as follows:

[0014] Step S1: according to the stoichiometric ratio of Ag 1-3x Bi x Nb 1-3x / 5 Y x O3 formula, Ag2O, Nb2O5, Bi2O3 and Y2O3 are weighed, wherein 0 < x ≤ 0.01;

[0015] Step S2: Put the weighed chemicals into a star-shaped ball mill, and add anhydrous ethanol as a medium for ball milling and drying;

[0016] Step S3: The mixed powder is pre-sintered at 850-950℃ under oxygen atmosphere at a heating rate of 3-5℃ / min for 3-9h, then the pre-sintered powder is ball milled and dried, and then the pre-sintered powder is subjected to isostatic pressing, and then pressed into a cylindrical embryo;

[0017] Step S4: The pressed cylindrical embryo is sintered again at 1050-1070℃ under oxygen atmosphere at a heating rate of 3-5℃ / min for 3-9h, and then cooled to room temperature at a cooling rate of 3-5℃ / min to obtain Ag 1-3x Bi x Nb 1-3x / 5 Y x O3 energy storage ceramic material.

[0018] Preferably, the purity of Ag2O in step S1 is 99.7%, the purity of Nb2O5 is 99.99%, the purity of Bi2O3 is 99.9%, and the purity of Y2O3 is 99.9%.

[0019] Preferably, the ball milling process of step S2 is ball milling at a speed of 300-600r / min for 18-24h.

[0020] Preferably, the pressing process of step S3 is to press a cylindrical embryo with a diameter of 8mm and a thickness of 1mm under an isostatic pressure of 200MPa.

[0021] The Bi 3+ and Y 3+ co-doped AgNbO3 antiferroelectric energy storage ceramic material in the preparation of ceramic capacitors.

[0022] Compared with the prior art, the present application has the following advantages and beneficial effects: the present application can effectively improve the stability of the AFE phase of the AgNbO3 energy storage ceramic material by co-doping ions at the A / B sites of the AgNbO3 energy storage ceramic material to reduce the tolerance factor (t);

[0023] Compared with the prior art, the present application has the following advantages and beneficial effects: the present application can effectively improve the stability of the AFE phase of the AgNbO3 energy storage ceramic material by co-doping ions at the A / B sites of the AgNbO3 energy storage ceramic material to reduce the tolerance factor (t); 3+ and Y 3+ In the present application, the long-range antiferromagnetic order in the AgNbO3 system is destroyed by adopting multiple Bi 3+ and Y 3+ doping strategies, the relaxation behavior is induced, the dielectric relaxation effect is increased, the polar nanoregions (PNRs) are formed, the P-E curve is relatively fine, and the energy storage efficiency can be effectively improved. b The present application can effectively improve the energy storage density and the stability of the antiferromagnetic phase at room temperature by improving the stability of the antiferromagnetic phase, improving the dielectric breakdown strength, and the synergistic effect of the relaxation characteristics. r The Ag 0.97 Bi 0.01 Nb 0.994 Y 0.01 O3-based relaxor antiferromagnetic energy storage ceramic prepared in the present application can obtain an energy storage density of 5.4 J / cm 3 and a conversion efficiency of 56% under the action of 190 kV / cm, which is about 4 times that of the AgNbO3 ceramic. This is consistent with the demand for miniaturization, integration and lightweight pulse power devices. BRIEF DESCRIPTION OF DRAWINGS

[0024] Figure 1 The X-ray diffraction patterns of the AgNbO3 energy storage ceramic material and the Ag 0.97 Bi 0.01 Nb 0.994 Y 0.01 O3 energy storage ceramic material.

[0025] Figure 2 The electric hysteresis loops of the AgNbO3 energy storage ceramic material and the Ag 0.97 Bi 0.01 Nb 0.994 Y 0.01 O3 energy storage ceramic material under different electric fields.

[0026] Figure 3 Energy storage parameters of AgNbO3 energy storage ceramic materials under different electric fields. 0.97 Bi 0.01 Nb 0.994 Y 0.01 O3 energy storage ceramic materials. DETAILED DESCRIPTION

[0027] The above content of the present application is further described in detail through the following examples, but this should not be understood as the scope of the above subject matter of the present application being limited to the following examples only, and any technology realized based on the above content of the present application falls within the scope of the present application.

[0028] Comparative Example 1

[0029] Step S1: Ag2O with a purity of 99.7% and Nb2O5 with a purity of 99.9% were weighed according to the stoichiometric ratio of AgNbO3, and the amount of substance of the AgNbO3 sample was 0.02 mol;

[0030] Step S2: the weighed chemical reagents were put into a star-shaped ball mill, 40 mL of anhydrous ethanol was added as a medium, the rotation speed of the star-shaped ball mill was set to 300 revolutions per second, the ball milling time was 24 h, and then drying was performed;

[0031] Step S3: the mixed powder was pre-sintered at 900℃ under an oxygen atmosphere at a heating rate of 5℃ / min for 6 h, the pre-sintered powder was then secondarily ball milled and dried, and then the pre-sintered powder was subjected to isostatic pressing treatment, and was pressed into a cylindrical body with a diameter of 8 mm and a thickness of 1 mm under a pressure of 200 MPa;

[0032] Step S4: the pressed cylindrical body was sintered again at 1070℃ under an oxygen atmosphere at a heating rate of 5℃ / min for 6 h, and then cooled to room temperature at a cooling rate of 5℃ / min to obtain the AgNbO3 energy storage ceramic material.

[0033] Figure 1 Fig. 1(a) is an X-ray diffraction pattern of the AgNbO3 energy storage ceramic material, and it can be seen from the figure that the sample presents a single perovskite structure with a pbcm space group, and no second phase appears.

[0034] From Figure 2 Fig. 2(a) and Figure 3 Fig. 2(b) are the electric hysteresis loop and energy storage parameter data diagram of the AgNbO3 energy storage ceramic material, and it can be seen from the figures that the maximum polarization strength P max = 24.5 mC / cm 2 of the AgNbO3 energy storage ceramic material under the maximum polarization electric field of 140 kV / cm is 45%, and the energy storage density W rec=1.4J / cm 3 .

[0035] Comparative Example 2

[0036] Step S1: Press Ag 0.97 Bi 0.01 The stoichiometric ratios of Ag₂O (99.7% purity), Bi₂O₃ (99.9% purity), and Nb₂O₅ (99.9% purity) were weighed to prepare Ag₂O₃. 0.97 Bi 0.01 The amount of NbO3 sample was 0.02 mol; the remaining steps were the same as in Comparative Example 1.

[0037] Figure 1 (b) is Ag 0.97 Bi 0.01 The X-ray diffraction pattern of the NbO3 energy storage ceramic material shows that the sample exhibits a single perovskite structure with the pbcm space group, without the appearance of a second phase.

[0038] from Figure 2 (b) and Figure 3 As can be seen from the hysteresis loop and energy storage parameter data in (b), Ag 0.97 Bi 0.01 The maximum polarization intensity P of NbO3 energy storage ceramic material under a maximum polarization electric field of 168 kV / cm max =54.6μC / cm 2 Energy storage density W rec =2.54J / cm 3 The energy storage efficiency η = 45.7%.

[0039] Comparative Example 3

[0040] Step S1: Press AgNb 0.994 Y 0.01 The stoichiometric ratios of Ag₂O (99.7% purity), Nb₂O₅ (99.9% purity), and Y₂O₃ (99.9% purity) were weighed to prepare AgNb 0.994 Y 0.01 The amount of O3 sample was 0.02 mol; the remaining steps were the same as in Comparative Example 1.

[0041] Figure 1 (c) is AgNb 0.994 Y 0.01 The X-ray diffraction pattern of the O3 energy storage ceramic material shows that the sample exhibits a single perovskite structure with the pbcm space group, with no second phase present.

[0042] from Figure 2 (c) and Figure 3As can be seen from the hysteresis loop and energy storage parameter data in (c), AgNb 0.994 Y 0.01 The maximum polarization intensity P of O3 energy storage ceramic material under a maximum polarization electric field of 185kV / cm max =48.15mC / cm 2 Energy storage efficiency η = 50%, energy storage density W rec =2.56J / cm 3 .

[0043] Example 1

[0044] Step S1: Press Ag 0.97 Bi 0.01 Nb 0.994 Y 0.01 The stoichiometric ratios of Ag₂O (99.7% purity), Nb₂O₅ (99.9% purity), Bi₂O₃ (99.9% purity), and Y₂O₃ (99.9% purity) were weighed to prepare Ag₂O₃. 0.97 Bi 0.01 Nb 0.994 Y 0.01 The amount of O3 in the sample was 0.02 mol.

[0045] Step S2: Place the weighed chemicals into a star-shaped ball mill, add 40 mL of anhydrous ethanol as the medium, set the speed of the star-shaped ball mill to 300 rpm, the milling time to 24 h, and then dry.

[0046] Step S3: The mixed powder is heated to 900℃ for 6 hours under an oxygen atmosphere at a heating rate of 5℃ / min. The pre-sintered powder is then ball-milled and dried. The pre-sintered powder is then subjected to isostatic pressing and pressed into a cylindrical blank with a diameter of 8mm and a thickness of 1mm using a pressure of 200MPa.

[0047] Step S4: The pressed cylindrical preform is heated to 1070℃ and sintered again for 6 hours in an oxygen atmosphere at a heating rate of 5℃ / min, then cooled to 300℃ at a cooling rate of 5℃ / min, and then cooled to room temperature in the furnace to obtain Ag. 0.97 Bi 0.01 Nb 0.994 Y 0.01 O3 energy storage ceramic materials.

[0048] Figure 1 (d) is Ag 0.97 Bi 0.01 Nb 0.994 Y 0.01The X-ray diffraction pattern of the O3 energy storage ceramic material shows that the sample exhibits a single perovskite structure with the pbcm space group, without any second phase. Figure 2 (d) and Figure 3 As can be seen from the hysteresis loop and energy storage parameter data in (d), Ag 0.97 Bi 0.01 Nb 0.994 Y 0.01 The maximum polarization intensity P of O3 energy storage ceramic material under a polarization electric field of 190 kV / cm max =78.5C / cm 2 Energy storage density W rec =5.4J / cm 3 The energy storage efficiency η = 56%.

[0049] In summary, this invention employs a solid-state reaction method to react Bi... 3+ Introducing position A, Y 3+ By introducing the B site, high-performance Ag was finally prepared. 1-3x Bi x Nb 1-3x / 5 Y x O3 (0 < x ≤ 0.01) energy storage ceramic materials significantly improve their E b W rec Through compositional design, AgNbO3-based relaxor antiferroelectric energy storage ceramic materials with antiferroelectric phase stability, high energy density, and high energy storage efficiency were obtained, providing a practical preparation scheme for their application in the field of high-performance ceramic capacitors.

[0050] The above embodiments describe the basic principles, main features, and advantages of the present invention. Those skilled in the art should understand that the present invention is not limited to the above embodiments. The embodiments and descriptions in the specification are only illustrative of the principles of the present invention. Various changes and modifications can be made to the present invention without departing from the scope of the principles of the present invention, and all such changes and modifications fall within the protection scope of the present invention.

Claims

1. A Bi 3+ and Y 3+ co-doped AgNbO3 antiferroelectric energy storage ceramic material, characterized by: The energy storage ceramic material has a chemical formula of Ag 1-3x Bi x Nb 1-3x / 5 Y x O3, wherein 0 3+ and Y 3+ The energy storage ceramic material is an A / B co-doped AgNbO3 antiferroelectric ceramic material.

2. The Bi 3+ and Y 3+ Co-doped AgNbO3 antiferroelectric energy storage ceramic material, characterized in that: The energy storage ceramic material has a chemical formula of Ag 0.97 Bi 0.01 Nb 0.994 Y 0.01 O3, an energy storage density W rec = 5.4 J / cm 3 , a conversion efficiency η = 56%, and a breakdown field strength E b = 190 kV / cm.

3. A Bi 3+ and Y 3+ The preparation method of the co-doped AgNbO3 antiferroelectric energy storage ceramic material is characterized by comprising the following steps The specific steps are as follows: Step S1: Ag 1-3x Bi x Nb 1-3x / 5 Y x O3 stoichiometric ratio of Ag2O, Nb2O5, Bi2O3 and Y2O3, respectively, wherein 0 < x < 0.01; Step S2: Put the weighed chemical into a star-shaped ball mill, and then add anhydrous ethanol as a medium to perform ball milling and drying; Step S3: Heat the mixed powder to 850-950°C at a heating rate of 3-5°C / min in an oxygen atmosphere for 3-9h for pre-sintering, then perform secondary ball milling and drying on the pre-sintered powder, and then perform isostatic pressing treatment on the pre-sintered powder, and then press into a cylindrical body; Step S4: The pressed cylindrical shaped green body is sintered again under oxygen atmosphere at a temperature increasing rate of 3-5°C / min to 1050-1070°C for 3-9h, and then cooled down to 280-320°C at a temperature decreasing rate of 3-5°C / min, and then furnace cooled to room temperature to obtain Ag 1-3x Bi x Nb 1-3x / 5 Y x O3 energy storage ceramic material.

4. The Bi 3+ and Y 3+ The preparation method of the co-doped AgNbO3 antiferroelectric energy storage ceramic material is characterized by comprising the following steps: The purity of Ag2O in step S1 is 99.7%, the purity of Nb2O5 is 99.99%, the purity of Bi2O3 is 99.9%, and the purity of Y2O3 is 99.9%.

5. The Bi 3+ and Y 3+ The preparation method of the co-doped AgNbO3 antiferroelectric energy storage ceramic material is characterized by comprising the following steps: The ball milling process in step S2 is ball milling at a speed of 300-600r / min for 18-24h.

6. The Bi 3+ and Y 3+ The preparation method of the co-doped AgNbO3 antiferroelectric energy storage ceramic material is characterized by comprising the following steps: The pressing process in step S3 is pressing into a cylindrical body with a diameter of 8mm and a thickness of 1mm under a pressure of 200MPa.

7. The Bi of claim 1 or 2 3+ and Y 3+ Use of the co-doped AgNbO3 antiferroelectric energy storage ceramic material in the preparation of a ceramic capacitor.

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